1) Somebody whose not from Boston (primarily Charlestown) who has taken residence there in recent years.
2) A person from outside the Greater Boston area who has moved into a tradition-heavy Boston neighborhood like Charlelstown, Dorchester, Cambridge, or any surrounding burrough.

Townie 1: You still take your kids to the Boys and Girls Club?
Townie 2: Yeah, they just got some new Toonie chick working there, great ass but her accent's goofy as fuck.